This question already has an answer here:
Is there a way to definitively tell what application is attempting to open a file on startup (if it is not in the Startup folder)?
For example, when I boot my PC, I see the following message:
My first step was of course to check the Startup folder. Nothing there (checked hidden files, too).
I've looked through MSCONFIG startup services and none of them are related to the filetype. I've run in Safe Mode and the file does not open, but that still doesn't tell me what is calling the file on startup.
I can open up task manager while the "Windows can't open this file" window is open, but that still doesn't tell me which of the running programs has called it.
I've even tried searching for the file in hopes of deleting it, but every search I've ran for it has turned up nothing.